Barometer.



W. SCHOKE;

BAROMETER. APPLICATION FILED FBB.1, 1910.l

Patented Feb. 21, 1911.

UNITED STATES PATENT OFFICE.

WILHELM SCHOCKE, 0F CASSEL, GERMANY.

BAROMETER.

To all whom 'it may concern:

Be it known that I, WILHELM SCI-rooms, a subject of the German Emperor, residing at Cassel, in the Province of HesseNassau, Kingdom of Prussia, and Empire of Germany, have invented new and useful Improvements in Barometers, of which the following is a specification.

In order to find out the eXact mercury level in the barometers used at the present time it is necessary to purposely regulate the scale every time we intend to rea-d off, as the surface of the mercury in the mercury con- Jrainer known as the lower mercury level which represents the zero point on the scale is not always of the same height, it being raised by the entrance of mercury into the container while the column of mercury is falling, and being lowered when the column of mercury is rising.

My invention avoids that previously necessary adjustment of the scale by variably positioning the scale or vessel and -by compensat-ing the differences of height of the lower mercury level, so that there is an automatic regulation whereby mistakes in the indication of the upper level upon the scale are avoided.

Figures l, 2, 3, of the accompanying drawing indicate a device showing the vessel Containing the mercury in a movable condition. Figs. 4, 5, 6 illustrate a movable condition of the scale. Fig. 7 represents a very practical suggestion for the demarkation of.

the upper mercury level upon the scale.

According to Fig. 1 a firm Zero point is obtained by having the mercury container floating in a jar filled with any fluid for eXa 1nple glycerin. According to the variation of the pressure of the atmosphere the quantity of mercury in the container will be increased or diminished by the quantity of mercury that will rise in or fall .from the column of mercury in the tube. The container therefore loses or gains in weight.

Taking into consideration the specic gravity of the fluid in the jar, and the proper circumference and horizontal cross Y section of the bottom of the mercury container, a, an equilibrium may be established, so, that by a diminution of weight of the mercury container it is raised and by an increase of weight of the mercury container it is lowered and the decrease or increase in its weight will amount to exactly as much as is necessary to obtain the same lower mercury Specification of Letters Patent.

Application led February 21, 1910.

Patented Feb. 21, 1911.

Serial No. 545,192.

i level at all times thus obtaining a stable zero point for the scale. In this case it is not necessary that the scale should be movable. The same result is obtained if the mercury container, a, is mounted upon a weighted lever, 7c, Fig. 2, act-ing` at the end of the lever or upon a spring, CZ, Fig. 3. If care is taken in calculating exactly the weight to act upon the lever or the force of t-he spring (Fig. 3) the result will be, that irrespective of the increase or decrease of the volume and weight of the mercury in the container the height of the lower mercury level will remain the same.' If in the other way the scale is brought into a movable position as illustrated in Figs. 4, 5, 6 it is clear that, although the differences in the -heights of the lower mercury level are not avoided, they will in no way interfere in the indication of the. level ofthe mercury column, because the scale itself is floating in the mercury of the mercury container, and by being raised or lowered it regulates automatically the position of the scale and with it the zero point by direct transmission.

The mercury container can be movable. It is suicient that the scale is Heating upon or in the mercury. The end of the scale acting as float, is made from or covered by a material to which mercury adheres and the size is proportioned to correspond to the weight of the scale.

In order to diminish the weight of the scale as much as possible counterweight's, c, Fig. 4 and Fig. 5, can be used, brought int-o action by the help of a grooved wheel, f, as shown in Fig. 4 or a lever, g, as shown in Fig. 5. The grinding of the scale in general is best controlled by guides, 7L, Figs. 4 6, which move very easily.

At the time of shipping it is necessary to close the opening in the mercury container in which the scale normally moves freely. In order to prevent the escape of mercury during shipment Jthe scale with its reinforced end Fig. 6 is pulled upward into the opening of the cover of the mercury container where it meets with a rubber ring, r, and closes tightly.

The tube in which the mercury column is situated is closed in the usual way by a rubber pad, Z, Fig. 6.

In barometers used before one straight mirror placed behind the enlarged upper end ofthe mercury tube was used for better recognition of the summit of the mercury column.V In this mirror we see the empty part of the glass tube and the observer is forced to bring his eye exactly into the Same height of the real mercury summit in order to avoid mistakes vin the fixation of the horizontal bar, p, Fig. T, the lower edge of which seems to touch Vthe summits which appear one behind the` other.

Instead of a straight mirror in the back as mentioned above I invented the applica- Y tion of one or better two angularly directed mirrors postero-laterally arranged, w-n, Fig. 6 and F ig. 7, for better indication which make visible the relected summits laterally to the true mercury summit. In this wayz we can much'more clearly and easily see one or more summits to 'the .side of the column inthis angular mirror and the summit is much more accurately indicated than in a -straight mirror placed straight behind the column.

Having'- now fully described my invention I claim:

vl.' In combination, a barometer. having a tube and a mercury container, and a scale for indicating the height of the mercury in the tube, and means whereby the relative fif position of the scale and container are autube and a mercury container, and a scale for indicating the height of the mercury point for the scale is obtained by direct transmission, thus 'saving a special adjust# ment or pair of readingsb'efore every separate determination of the real mercury level substantially as describedand shown and for the purpose set forth.

` 3. In combination, a barometer vhaving a tube and a scale for indicating the height of the mercury in the tube and provided with a reinforced end, anda mercury con-y tainer provided with an opening for the free passagev of the scale, said reinforced end of the scale tightly fitting into said opening ofthe container and means coperating with the said re-inforced end for preventing the escape of mercury during shipment substan tially as described and shown.

4L. In combination a mercurial barometer having a tube anda scale for indicating the height of the mercury in the tube and 'mirrors for producing reflection of the true v summit ofl the mercuryicolumn, said mirror placed in an angular direction postero-laterally and parallel .to the tube and mercury column by means of which angular` direction of the mirrors the reiected summits of the mercury column appear. laterally tothe mercury tube substantially as described and shown and for the purpose set forth.

VILHELM SCI-IOCKE.

` IVitnesses: AUGUST BETHGE,

JANS FLINDMER.

l inthe tube, said scale at its lower end loat- 

